I support and LOVE LOVE LOVE the Ichigo/Rukia pairing in Bleach. This time, I'm not going to yell out how much I love them, but perhaps give you evidence and formulations of my own opinions on their awesome relationship ^^ but Im not a very um professional writer, so ya >.> excuse my bad grammer.
A confession: I'm generally not a Bleach fan, to tell you the truth, Im not too passionate about Bleach (ask anyone that), but this pairing is very very important to me. I think that Ichigo and Rukia are the cutest couple and when I first read Bleach, I remember thinking "God this is a perfect couple.." Rukia is one of those people who really makes me go "wow" because of her personality and appearance, but then there is Ichigo, who, to me, seems like an everyday sort-of-guy & no-one really compared to Byakuya or those cool Soul Society people, but you knew from the FIRST time you saw them that they were meant to be together.
Whenever Rukia saved Ichigo I was totally in awe, and especially when she left him and went to Soul Society, I was totally bawling. In reality, I dont really support any sort of relationship of Bleach except for Byakuya (but the reason for that is because I love Byakuya-- and then Hinamori/Hitsugaya which is cute ^^ but romantically Im not really into any relationship). However, in the case of Ichigo and Rukia, the ONLY reason I read those non-Byakuya chapters was because of the Rukia and Ichigo relationship. I actually have this major theory about Ichigo and Rukia and why they were meant to be together. It was just not a coincidence that Rukia found Ichigo, they both needed each other, and Orihime, I dont like her that much :P even said that the person who made Ichigo who he was Rukia. Byakuya remarked on Rukia's behalf, clearly seeing the way Rukia had changed was because of Ichigo... Saying "so he is the one..." remember?
In general, Im not a very big fan of the people themselves, as much as I am of the pairing together. To tell you the truth lol, I joined the relationship fanlisting even before the Bleach fanlisting, because I thought it was the cutest thing and I actually love relationship fanlistings better than Series ones because they are so much more intimate and personal.
Back to why I love them, In most Shonen Manga you see one of the following: either the guy who protects the girl (so many I cant even tell), or the girl who abuses the guy (In Shaman King)), and then there is the relationship in which people are generally a 'couple' but don't really show it (like FMA lol-- the Winry and Ed relationship, or Sasuke who never tells Sakura he loves her-- one sided,), but, in the Ichigo/Rukia case, it's totally the exact opposite. There is no one sided relationship, neither is there some kind of thing in which the characters don't know how they feel for each other.
With Rukia/Ichigo they are saving each other, and interpreting each other like glass walls. Rukia knew that Ichigo would follow her, and told her not to come, but she already knew that he would come for her, as did Ichigo know why Rukia said everything she did say. They TOTALLY understand each other, and act upon those feelings, which is why I love them so much. It's not even that they are all head over heels in each other, they have this deep connection with each other and are meant to be through the past, present, and Im sure even in the future. I actually dream that one day I can meet someone like that you know ^^, like not lovey-dovey, but more of respect, understanding, because those are the kind of relationships that really last. Im not for the true-love-at-first site things. Its corny, and ya... hehe me, the non-romantic. I define true love as understanding, respect, and meeting someone who cares deeply for you by the respect and understanding. Someone who could understand you in everything ^^, and know WHAT to do, and When!
In my theory that I have formulated with Ichigo and his "look alike :P" I believe it's from Rukia's past that she was to be with Ichigo, and Ichigo who had to have his life changed by no one other than Rukia. I dont think Ichigo will ever forget Rukia, and I feel so sorry for him, because you can TOTALLY see how lonely he is in the later chapters without Rukia. I think actually if that relationship wasn't so strong Bleach wouldn't even be as good as series as it. Secretely I think the whole series is about Ichigo and Rukia (hehe... cause I mean, everything Ichigo DOES is mostly for Rukia, as Rukia does everything as she does because of Ichigo and truthfully if they didn't have that really close attachment to one another, it would work out totally different.). They are so much into each other they forget to even care about themselves, both Rukia and Ichigo, and it's sort of like, they change their own characteristics when it comes to each other. Ichigo, who seemingly cares for nothing really but was so PASSIONATE about going after Rukia, as well as truely opened up to Rukia about his history, his feelings... Rukia was someone he could share that with. Then, Rukia, who always had the hard demeanor, always brave and all-knowing, but shed tears a couple of times at the sight of Ichigo. Ichigo, who gave Rukia someone to care about.
I think they are the most perfect couple, they aren't a 'forbidden couple' (those couples that dont go together but are fun to think about :P Like Anna/Hao) but if I had to decide between any couple that was meant to be, romantically, friendship wise, and all that jazz in all of anime/manga, it would be Ichigo/Rukia...